Twenty-six police officers were injured in Mexico City on Monday during clashes with demonstrators who threw firecrackers.

The demonstrators were participating in a protest demanding justice for 43 students who disappeared in 2014 from the town of Ayotzinapa in southern Guerrero state.

Their anger was sparked by the recent release from pre-trial detention of eight soldiers suspected of being involved in the students’ disappearance.

The disappearance of the 43 students and the flawed investigation have long angered their families as well as human rights activists in Mexico and abroad.

City officials reported that 26 officers suffered injuries from the firecrackers, impacting their arms, legs, and buttocks, and were taken to the hospital for treatment.

The protesters dispersed after the clashes.

This is not the first time protesters have gathered at the Zócalo, the central square in the capital, to draw attention to the lack of progress in bringing those responsible for the students’ disappearance to justice.

In March, a group broke down one of the doors of the presidential palace with a truck, reportedly expressing their frustration at not being received by President Andrés Manuel López Obrador.

Solving this case was one of President López Obrador’s campaign promises, but nearly six years into his presidency, there has been little progress.

The 43 men, all students at an all-male teacher training college in Ayotzinapa, went missing on 26 September 2014 as they returned from a protest. Despite multiple investigations, only the remains of three of the 43 have been found.

The whereabouts of the remaining 40 are still unknown, and while some relatives continue to hope to find them alive, they are widely presumed dead.

Two years ago, Mexico’s undersecretary for human rights, Alejandro Encinas, stated that local, state, and federal officials had been involved in the students’ disappearance and called it a “state crime.”

He also claimed that the government at the time of the disappearance had attempted to cover up these connections and concluded that there was “no indication the students are alive.”

However, Mr. Encinas’s 2022 report has faced criticism from the families of the disappeared.

The families argue that the presidential commission led by Mr. Encinas did not investigate military intelligence documents, which they believe could provide information that would shed light on the case.

The military has denied the existence of such documents.

Families and human rights activists have held regular protests to keep pressure on the government to solve the crime.

The release of eight soldiers suspected of involvement in the case last Thursday infuriated those demanding justice for the 43, fearing the suspects could flee if they are not detained.

Prosecutors say the eight were on patrol in the area where the students went missing on the night of their disappearance.

They have been charged with forced disappearance and organized crime and are required to report to court twice a month.